Method and apparatus for coverage enhancement of sidelink synchronization signal block

Abstract

Systems and methods for coverage enhancements for sidelink (SL) synchronization signal block (SSB) (S-SSB) between a transmit (Tx) user equipment (UE) and a receive (Rx) UE are disclosed herein. S-SSB frequency domain enhancement may use frequency hopping for S-SSB and/or S-SSB that use an increased number of physical radio bearers (PRBs). S-SSB time domain enhancements may modify an S-SSB periodicity, a number of S-SSB per period, use a clear channel assessment (CCA) (or listen before talk (LBT)) procedure, and/or transmit only some of a configured set of S-SSBs for an S-SSB periodicity. Multi-beam S-SSB enhancement may index S-SSBs of a configured set and send those S-SSBs using beams corresponding to the indexes. S-SSB enhancement using frequency domain masking and/or time domain masking may apply different masks to one or more S-SSBs.

1 . A method of a user equipment (UE) for sidelink (SL) communications, comprising:
 selecting a first SL synchronization signal block (S-SSB) frequency hopping pattern; and   transmitting a first plurality of S-SSBs to a first peer UE according to the first S-SSB frequency hopping pattern.   
     
     
         2 . The method of  claim 1 , wherein synchronization signal identifiers (SSIDs) used by the first plurality of S-SSBs correspond to the first frequency hopping pattern. 
     
     
         3 . The method of  claim 1 , further comprising:
 selecting a second S-SSB frequency hopping pattern; and   transmitting a second plurality of S-SSBs to a second peer UE according to the second frequency hopping pattern.   
     
     
         4 . The method of  claim 3 , wherein:
 first synchronization signal identifiers (SSIDs) used by the first plurality of S-SSBs correspond to the first frequency hopping pattern; and   second SSIDs used by the second plurality of S-SSBs correspond to the second frequency hopping pattern.   
     
     
         5 . A method of a user equipment (UE) for sidelink (SL) communications, comprising transmitting a plurality of SL synchronization signal blocks (S-SSBs) in a frequency domain that is greater than eleven physical resource blocks (PRBs). 
     
     
         6 . The method of  claim 5 , wherein each of the plurality of S-SSBs comprise more than 11 PRBs. 
     
     
         7 . The method of  claim 5 , wherein the plurality of S-SSBs comprises repeated S-SSBs in the frequency domain. 
     
     
         8 . A method of a first user equipment (UE) for sidelink (SL) communications, comprising:
 receiving, from a second UE, one or more indexes corresponding to a configured set of SL synchronization signal blocks (S-SSBs); and   receiving, from the second UE, one or more S-SSBs, each of the one or more S-SSBs indicating a corresponding index of the one or more indexes;   wherein each of the one or more S-SSBs is transmitted by the second UE according to a beamforming corresponding to the corresponding index.   
     
     
         9 . The method of  claim 8 , wherein each of the one or more S-SSBs implicitly indicates the corresponding index based on a transmission timing. 
     
     
         10 . The method of  claim 8 , wherein each of the one or more S-SSBs indicate the corresponding index in a physical sidelink broadcast channel (PSBCH) payload. 
     
     
         11 . The method of  claim 8 , wherein:
 each of the one or more S-SSBs indicates a first portion of the corresponding index in a physical sidelink broadcast channel (PSBCH) payload; and   each of the one or more S-SSBs indicates a second portion of the corresponding index using one of physical sidelink broadcast channel (PSBCH) scrambling, cyclic redundancy check (CRC) scrambling, and locations of PSBCH demodulation reference signals (DMRSs) within the one or more S-SSBs.   
     
     
         12 . The method of  claim 8 , wherein each of the one or more S-SSBs indicates the corresponding indexes using sequences found in the one or more S-SSBs. 
     
     
         13 . The method of  claim 8 , wherein each of the one or more S-SSBs transmits each of its symbols according to one or more of: a same Doppler spread; a same Doppler shift; a same average delay; a same delay spread; and a same spatial receive (Rx) parameters. 
     
     
         14 . The method of  claim 8 , wherein each of the one or more S-SSBs is transmitted with a same power. 
     
     
         15 . The method of  claim 8 , wherein a current S-SSB of the one or more S-SSBs indicating a same corresponding index as a prior S-SSB of the one or more S-SSBs is transmitted according to one or more of: a same Doppler spread used to transmit the prior S-SSB; a same Doppler shift used to transmit the prior S-SSB; a same average delay used to transmit the prior S-SSB; a same delay spread used to transmit the prior S-SSB; same spatial receive (Rx) parameters used to transmit the prior S-SSB; and a same power used to transmit the prior S-SSB. 
     
     
         16 . The method of  claim 8 , wherein at least one of the one or more S-SSBs is configured to be used for one or more of: a first reference signal for quasi-colocation; a second reference signal for a path loss estimate; a third reference signal for radio link monitoring (RLM); a fourth reference signal for beam failure detection (BFD); and a fifth reference signal for candidate beam detection (CBD). 
     
     
         17 - 42 . (canceled)